Donor breastmilk (DBM) is the recommended second choice of enteral feed for preterm infants.1 The aim of this study was to develop a simple protocol for the determination of the macro nutrient composition of DBM in a human milk bank.
There are wide variations in the nutritional composition of DBM. In addition to individual variation, the donors have babies of differing ages and they express their milk at varying times of the day and night (sometimes between feeds and sometimes at the end of feeds). Fat separates readily from the aqueous phase in breastmilk that has been previously frozen and thawed, especially if the milk remains chilled as required by UK guidelines.2 Analysing a sample of milk taken from every container would be time consuming, costly and wasteful of milk. In the UK it is usual for 500–1000 ml pools of a single mother’s milk to be gently mixed prior to dividing it into 50–100 ml aliquots ready for pasteurisation.
To enable nutritional analyses of donor milk to be successfully introduced into the standard milk bank procedures it was necessary to demonstrate that a sample of milk taken at a predetermined point during the pooling and aliquoting process would be nutritionally representative of every aliquot to which the resultant analysis would be applied.
A final protocol is presented that enables milk banks to provide accurate data for each container of DBM.